autolayout - UIAlertView 给出约束错误

Question

我有以下代码，当我的应用程序出现问题时，会显示包含不同消息的警报。该代码多年来一直运行良好，并且存在于我在 App Store 上的大多数应用程序中。

我正在制作一个新应用程序，只是添加了此代码，但是我在控制台中看到下面的错误消息，我无法摆脱它。

约束消息是指警报宽度，但我没有设置约束，也无法调整任何约束来消除警告。

有人可以告诉我出了什么问题吗？

谢谢

-(void)errorMessage:(id)sender
{

    UIAlertController *alert = [UIAlertController alertControllerWithTitle:NSLocalizedString(@"Information",)
                                                                   message:displaymessage
                                                            preferredStyle:UIAlertControllerStyleActionSheet];
    UIAlertAction *firstAction = [UIAlertAction actionWithTitle:NSLocalizedString(@"OK",)
                                                          style:UIAlertActionStyleDefault handler:^(UIAlertAction * action) {
                                                              [self dismissViewControllerAnimated:NO completion:nil];
                                                          }];

    [alert addAction:firstAction];
    [self presentViewController:alert animated:YES completion:nil];
}

2019-04-18 09:17:54.785207+0100 TestInputView5[1380:28232] [LayoutConstraints] Unable to simultaneously satisfy constraints.
    Probably at least one of the constraints in the following list is one you don't want. 
    Try this: 
        (1) look at each constraint and try to figure out which you don't expect; 
        (2) find the code that added the unwanted constraint or constraints and fix it. 
(
    "<NSLayoutConstraint:0x600001e15b30 UIView:0x7fe60c6104e0.width == - 16   (active)>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x600001e15b30 UIView:0x7fe60c6104e0.width == - 16   (active)>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKitCore/UIView.h> may also be helpful.

Answer 1

我在俄罗斯论坛上找到了解决方案。它看起来像魔法，但确实有效。你需要做两件事:1)向警报添加空 View 2)不带动画显示

alert.view.addSubview(UIView()) // I can't explain it, but it works!

self.present(alert, animated: false)

论坛致谢:https://quares.ru/?id=33972

这篇文章是机器翻译的，所以我想应该有英文原文(我找不到)